Negotiators in the Senate and House of Representatives will convene Wednesday to begin resolving differences in a long-delayed farm bill. It won’t be easy.

The 41-member panel must bridge a huge divide in the five-year, $500 billion reauthorization bill’s most contentious issue: cuts to the Supplemental Nutrition Assistance Program, commonly called food stamps.

The Republican-controlled House passed a bill that would cut food stamps by $39 billion out of a projected $800 billion over 10 years. In addition, the House SNAP provision would require able-bodied adults without children to work or volunteer for 20 hours a week to receive federal assistance.

The Democratic-held Senate’s farm bill also would cut food stamps, but by $4.5 billion over a decade. The Senate plan wouldn’t add work requirements.

“I hope they can find a way to thread the needle,” said Sen. John Thune, R-S.D., one of the conferees. “I hope we can figure it out, because there’s too much riding on passing the farm bill to allow the nutrition title to derail it.”

The differences over food stamps could jeopardize a bill that sets farm policy and covers conservation programs, insurance and farm subsidy programs. In addition to the food stamp controversy, there are lesser disputes over a measure in the Senate bill that would lower crop insurance subsidies by 15 percentage points to farmers with gross adjusted incomes over $750,000 a year.

The Senate bill also would require farmers who receive crop insurance to meet certain environmental standards. The House bill does not.

It’s been a tough slog for the farm bill, which was authorized in 2008 and expired last year. Congress extended it through September, hoping to buy more time to reach a deal.

If the conference committee fails to produce something for the House and Senate to vote on by the end of the year, consumers might feel the impact. Dairy supports are set to expire, meaning the cost of milk could jump significantly if a new farm bill isn’t in place.

“There are certainly going to be battles to work things out,” said Dale Moore, the executive director for public policy at the American Farm Bureau. “Congress needs to do something.”

More than anything else, the talks face a division over how to cut food stamps.

House Speaker John Boehner, R-Ohio, appointed Rep. Steve Southerland, R-Fla., to the conference committee. Southerland, who isn’t a member of the House Agriculture Committee, is a driving force behind the work provision. He views the requirement as “a moral issue.”

“There have been people who have not been allowed to be initiated to the beauty of work,” Southerland said. “I don’t know where the happy medium is, because obviously there are differences between the two bills. The nutrition talks could be one of the most volatile – if not the most volatile – component.”

Several Democratic lawmakers say they aren’t in a compromising mood. They said the House cuts would harm needy Americans. The number of people who receive food stamps has mushroomed from 26.3 million in 2007 to 47.6 million this month, according to U.S. Department of Agriculture figures.

“The conferees will have to make a choice. This isn’t about splitting the difference; that’s a nonstarter,” said Rep. Jim McGovern, D-Mass., a conferee and House Agriculture Committee member. “This is about whether you want a farm bill that makes hunger worse or one that combats hunger.”

As for the work requirement, McGovern said, “I think what Congressman Southerland has done is kind of a nasty attack against low-income people. The notion that people somehow like being on SNAP is ridiculous.”

Thirty-nine liberal Democratic senators sent a letter to the conference committee Monday imploring it to reject both the House and Senate food stamp provisions.

“While we support efforts to improve the integrity of the SNAP program, we encourage conferees to reject all SNAP eligibility to erect new barriers to participation, preventing millions of seniors, children and families from accessing food assistance,” said the letter, organized by Sen. Kirsten Gillibrand, D-N.Y.

In the end, Thune said, House and Senate negotiators and the rest of Congress are going to have to compromise and find a comfort zone.

What “the speaker in the House is going to have to figure out is how they get to 218 votes and what does that mean,” he said. “If you make movements one way or the other, you start losing votes on one side or the other.”